Identification of major contamination sources during processing of emulsion sausage

The extent of contamination of an emulsion type of sausage with lactic acid bacteria was determined along the processing line. This was done by aseptically removing sausages after five different processing stages (heat processing, chilling, cold storage, cutting down and packing). Removed sausages were vacuum-packed and stored at 8 degrees C. The microbial growth was followed during storage and the microbiological shelf-life obtained at the different stages of the processing was determined. The spoilage flora of stored sausages was identified/grouped. Two major hygienic problems were identified: (1) a heat tolerant flora of Lactobacillus viridescens which survived the heat processing and was never outgrown by the recontaminating flora; (2) recontamination with a flora dominated by Lactobacillus sp. group 5, which occurred in the cold storage room; this flora dominated in the absence of L. viridescens. The heat tolerant L. viridescens SMRICC 193 survived at 68 degrees C for 40 min. Being exposed to a slowly increasing temperature, only a 10 cfu/ml decrease took place when the temperature increased from 60 degrees C to 70 degrees C over a period of 30 min.